Variable delivery alternating piston pump



Aug. 26, 1947. T. J. LESTER 2,426,361

VARIABLE DELIVERY ALTERNATING PISTON PUMP I Filed Dec. 9, 1942 e Sheets-Sheet 1 B 'ai'g 3 9, .?a\' 3 In w i g, 9 4" p D H @M INVENTOR. THOMAS J.LESTER AITTORNEYS Aug 2fi, 1947.

VARIABLE DELIVERY ALTERNATING PISTON PUMP Filed Dec. 9, 1942 6 SheetQs-Sheet :s

INVENTOR. moms .LLESTER T; J. LESTER v 2,426,361

BY Y Y ATTORNE Aug. 26, 1947. T LESTER 2,4265361 I I VARIABLE DELIVERY ALTERNATING'PISTON PUMP Filed Dec. 9, 1,942 e Sheets-Shet 4 v l fizz 13.14: I z

INVENTOR.

THOMAS J.LESTER AITQRNEYS Aug. 26, 1947. J, LESTER 2,426,361

VARIABLEDELIVERY ALTERNATING PIS TON PUMP Filed Dec. 9, 1942 6 Sheets-Sheet 5 DELIVERY INTAKE INVENTOR ATTORNEYS THOMASJ.LEST'ER wig-MA Aug. 26, 1947.

' T. J. LESTER VARIABLE DELIVERY ALTERNATING PISTON PUMP Filed Dec. 9 1942 INTAKE 6 Sheets-Sheet 6 INVENTOR.

THOMAS JY.LESTER ATTORNEYS Patented Aug. 26, 1947 VARIABLE' DELIVERY ALTERNATING PISTON PUMP Thomas J. Lester, Shaker Heights, Ohio, assignor' to Lester Engineering Company,

Cleveland,

Ohio, a corporation of Ohio Application December 9, 1942,. Serial No. 468,370

The present invention relates to a variable delivery pump, or equivalent power mechanism, of the rotary type and embodying a novel fluid displacement principle in which concentrically rotating elements are caused to have an oscillating movement with respect to each other inorder to effect a double acting fluid displacement action. My invention can hence be said to comprise a unique combination ofrotary and oscillatory motions.

Prior forms of rotary pumps have required relatively complicated and expensive manufacturing operations, and have necessitated a large number of carefully fitted and precisely made moving parts. Furthermore, in the case of the eccentric rotor, radial piston and movable vane types of rotary'pumps, the delivery or displacement action is neoessarily'limited to one stroke per-revolution. In the pump embodying my invention, on the otherhand, not only is the structureand' manufacture of the moving parts greatly simplified, but also there'is obtained a double acting delivery or displacement action in which two delivery strokes for each displacement chamber are accomplished per single revolution. i

The pump embodying the principle ofmy invention includes a rotor of' the fixed vane or win piston type which oscillates back and forth in an arcuate chamber or housing; thel'atter being also in the" form of a rotor an'd concentri'c with the vane piston rotor. As these tWo rotors both move through a single revolution and on the same axis, motion is sotransmitted' from one to the other as to produce a relative acceleration and deceleration therebetween, resulting in a back and forth or oscillatory movement of one rotor with respect to the other during each complete revolution. This transmission of rotary motion is accomplished through the medium of a third rotating element which is mounted upon an axis: parallel to, but eccentric to the common axis ofv the two-rotors. Variation in the eccentric position of this third rotating and rotary motion transmitting element in turn produces a variation in the amount of oscillation of one of the rotors with respect to each other, and hence, a variation in the length of the stroke of the vane piston-in its chamber, thereby efiecting variable delivery control of the pump.

A further object andadvantage of my-invention is to provide fluid intake and delivery passages through the commonaxis of the relatively oscillating rotors, together with ports associated with one of the rotors whereby an automatic valving of. theaintake and delivery strokes of the fluid displacement chambersris achieved.

Another object andadvantage of my invention is that the rate of travel of the vane piston in its chamber is substantially of the simple harmonic. type,- wherein the piston moves relatively slower 20 Claims. (01. 103-120) I at each endoi its-stroke than it does during the 65 the 1 principle? of my-invention mid portion thereof, thus tending to eliminate any sudden impact or hammering action as the piston begins and ends its stroke, thus producing arelatively smooth and even pumping flow. Furthermore, the above-mentioned, automatic valvingfeature of my invention is so constructed and arranged with respect to'this movement characteristicof the Vans; piston, that the intake and delivery orifices presented by the valve ports are larger and smaller in direct coincidence with the latent intake and delivery of the pump displacement chamber.

A further object of my invention is to provide a plurality of vane pistons and displacement chambers between the rotating and relatively oscillating rotors, whereby; in addition to the previously mentioned double acting displacement action of an individual vane piston, a plural number of fluid displacement strokes, delivering in sequence, arejobtained for each single revolution.

grammar objects and advantages of my invention shall become apparent during the course of fl the following detailed description.

To th'eaccomplishment of the foregoing and related en'ds, said invention,.then, consists of the means hereinafter fully described and particularly pointed out in the claims, the'annexed drawings and' the following description setting forth in detailflcertain means and one mode of carrying out-the invention, such disclosed means and mode illustrating, however, but one of various ways in Which-theprinciple of theinvention maybe used.

7 Insaid annexed drawings;

Fjig'." 1 is a longitudinal; sectional view taken through a; pumpiembo'dying t'he principle of my invention;

' Fig. '2', is asecti'on'al View taken substantially along liner-2 of Fig. 1;

Fig. 3-is a detailed, sectional'view taken in staggered planes and substantially along line 3-3 as indioated in'Fig. -1;

Figz-eis an endelevational detail of the vane piston rotor;

Fig. isa sectional view taken substantially along-line 5-'-5 oflFig. 4; g

fFigs; 6l'3;'incl., are simplified, more or less diagrammatic -views illustrating therotative operation of the major elements of my pump, and showing the-partsdurin'g one complete revolut-ioii, each of said-Figs.- 6-13, 'incL, showing such parts? at; -a-positio-'n of "rotation e5? removed 7 from the? other; an'd I 'Fig; is a geometrical? diagram illustrating Now referring'imore part'icularlytoFigs, l and 2 of the arming-5;: the" pump structure shown therein iincludesl an: outer :housing and" frame member Li i -ot'substantially cylindrical shape, with the co'ver..platesiland 3' attached thereto, such as by the cap screws 4. A fixed, hollow shaft 5 is attached to the cover plate 3 by means of the screws 6 engaging with the lateral flange 1 on the left-hand enlarged portion of such fixed shaft. The shaft 5 is hollow and divided by the central partition 8 into an intake passage 9 and a delivery or exhaust passage l0. Pipes or conduits II and I2 are connected into the left-hand or outer end of the passages 9 and I0, respec-.

tively.

At the right-hand or inner end of the shaft 5, the passages 9 and I are opened through the wall of the shaft to the outer surface thereof by means of the removed portions or ports l3 and I4, respectively.

The right-hand end of the shaft 5 is closed and also mounts the male conical pilot bearing l5.

The drive shaft I6 is journaled in the ball bearing I! which in turn is carried by the cover plate 2. The inner end of the drive shaft l6 has a female, conical pilot bearing l8 fitting over the bearing l5 of the fixed shaft 5; and also carries a flange or plate H! to which the inner rotor 20 is attached. The rotor 20 carries the rigid, fixed wings or vane pistons 2| which are drilled to receive the cap screws 22 which join the plate [9 on the end of the drive shaft IE to a similarly shaped plate 23 on the opposite side of the rotor 26. The bolts 22 thus serve as means for clamping the plates l9 and 23 together and also for regulating the pressure with which such plates are held against the radial side faces of the second rotor 24, to seal such meeting surfaces against fluid leakage.

The second rotor 24 surrounds the rotor 20 and is mounted rotatably or oscillatably thereon. The rotor 24 has radially, inwardly directed, fixed abutments 25 which are circumferentially spaced apart a greater arcuate distance than the width of the vane pistons 2|, thus forming fluid displacement chambers in which the pistons 2| are adapted to reciprocate.

A pair of ring members 26 and 21 are joined together by the spacer bosses 28, 28 and suitable fastening screws or bolts 29. The rings 26 and 21 have laterally outward projecting hubs 30 and 3|, respectively, which are journalled by means of the ball bearings 32 and 33 in the movable housing 35. The housing 35 includes a separable side Wall portion 34 which facilitates assembly of the parts. The housing 35 engages the frame housing at the slide bearing surfaces 36 and 31. Adjusting lock bolts 38 and 39 extend through the side of the frame I and-bear against the bosses 40 and 4|, respectively, of the slidable or movable housing 35. I

The inner rotor 2|! is rotatably connected to the rings 26 and 21 by means of the pivoted link arm 42. The link arm 42 is pivotally connected to the radially projecting portions l9 and 23' of the plates l9 and 23, respectively, and by means of the wrist pin 43. At the other end, the link arm 42 is pivotally connected to the rings 26 and 21 by means of the wrist pin 44.

The outer rotor 24 has a radially projecting portion 24' which in turn is connected by means of the wrist pin 45 to the link arm 46. The latter, it will be noted, is bifurcated to accommodate assembly to the rotor portion 24. The wrist pin 48, carried by the rings 26 and 21 connects the other end of the link arm 46 to such rings.

The inner rotor 20, as will be noted from Fig. 1, is mounted upon a cylindrical hub portion 20* whose left-hand end is journalled at 41 to the" inner, conical bearing on the fixedshaft 5, and

4 to the outer, ball bearing 49 mounted in the housing wall 3.'

By particular reference to-Fig. 2, it should be noted that the centers of the wrist pins 43 and are equi-distantly spaced from the common center of rotation of the rotors 20 and 24, which in turn, is the axis of the fixed shaft 5. Also, the centers of wrist pins 44 and 48 are equi-distantly spaced from the center of rotation of the rings 26 and 21, and are located at fixed points 180 removed, or diametrically opposite each other, on the rings 26 and. 21.

Referring now particularly to Figs. 3, 4 and 5, the inner rotor 20 has a pair of annular passages 50 and 5| which are located radially inward from the vane pistons 2|. The passage 56 has a port 52 and the passage 5| has a port 53, both of which ports are in radial alignment and communication with the openings I3 and I4 in the fixed shaft 5.

Assuming the rotor 20 to be rotating in a clockwise direction, as shown by the arrow in Fig. 3, communication passages or ports 54 are located just to the rear of the vane pistons 2| and in radial alignment with the annular passage or manifold 53. Ports 55 are located just in advance of the vane pistons 2| and are in communication with the annular passage or manifold 5|.

Thus, it will be seen, that as the rotor 20 is in the position as shown in Fig. 3, that fluid enters the intake passage 9, can pass therefrom through the port 52, to the annular manifold 50, through the ports 54 to the space or chamber to the rear of the vane pistons 2|. When the rotor 20 is in a position removed from that shown in Fig. 3, or advanced one-half a revolution therefrom, the

' port 52 is in communication with the delivery passage Ill, and similarly are the annular manifold 5G and ports 54 placed in communication with such delivery passage l6. By the same token, the port 53, annular manifold 5|, ports 55 and spaces or chambers. in advance of the vane pistons 2|, placed in communication with the delivery passage ||l when the rotor 26 is in the position of Fig. 3; and in communication with the intake passage 9 when advanced one-half a revolution.

The mode and principle of operation of the above-described invention is clearly illustrated in Figs. 6-13, incl. These figures show the essential elements of the pump, namely, the inner rotor 26, the outer rotor 2 2-, one of the eccentric control rings 26, and thelink arms 42 and 46. For the purpose of convenience in illustration, only one and the same vane piston 2| and one and the same abutment 25 are marked with reference numerals in Figs. 6-13, incl. The eccentric ring 26 is shown in these figures moved in a left-hand, horizontal direction so that the eccentricity of the center of the ring 26 is to the left of the common center of the rotors 26 and'24. Thus, the outer dot and dash circle A, passing through the pivot points of the links 42 and 46 on the eccentric ring 26, represents the path of travel of such pivot points; and the inner dot and dash circle B, passing through the points of pivotal attachment of the links 42 and 46 to the rotors 26 and 24, represents the path of travel of' the latter pivot points. The parts are assumed to be rotating in a. clockwise direction in Figs. 6-13, incl, and each'succeeding figure shows these partsin a position 45 of advanced rotation, so that an approximately complete cycle of revolution of 360 is illustrated in all eight figures. As indicated by the legends at the upper left-hand corner of the drawings upon 'Which'Figs. '6-13 occur, the fluid which is under pressure or being delivered,

eyiaaser from the pump: is represented by horizontal;

dotted lines, and the fluid being drawn into the: pump, viz., the intake; is represented by vertical link arm 52, in passing: from the position of Fig. 6"

to that of Fig. 7-, tends to'slow'down or de'celerate the rate of rotation of the ring 26. This slowing down is, in turn, transmitted from the link arm 36 to the rotor M, to cause the latter to rotate at a slower speed than the rotor 23: Thus; ineffect, the link arm 42 canbe'said to bepulling back ontherin'g 26; andthe'link arm d6 pushing back on the rotor 24. The: net result is that as the parts rotate through: 180, from the position shown in Fig. 6, to that shown in Fig. 10, the vane piston 25' has traveled from a position furthest removed from the abutment 2 3 to a position closest to it, thus forcing or displacing the fluid out through the port 55, into the manifold 5!, through the port 53, thence to the delivery passage Iii;

It will be noted that themovement of the vane piston 2 l with respect to the abutment 25:is relatively smaller as it goes from the positions of Figs. 6 and 7 and 9: and thanait is in going from the positions of Figs. 7 to 9. This means, of course, that the rate of travel of the piston 25 with respect tothe abutment 25 is faster in the mid portion of its stroke than it is adjacent each terminal end. Concurrently with the rotation of the parts in Figs. 6 10, it: will be seenthat the port 53 has just cleared the endof the baffle Wall 8. at the position of Fig. 6 (viz. has just come in registry with the delivery passage Hi). In the positions of Figs..7 and 8; the port 53 has fully cleared the end of the baille wall8 andzis in completely open and unobstructed position. Then, as

the vane piston 2i nears: the end of its stroke, the port 53 commences to be closed oifby'th'e other side of the baflle wal1'8, as shown in Fig. 9 (via, the port 53 begins to close with respect toth'eport M) I As the parts rotate from the position of Fig. 10to the position of Fig. 1 3,- the linka'r m42 ten'ds to push the eccentric ring 26 faster than the rate of rotation of the rotor 2'9 simultaneously, the link. arm. 56 tends to pull forward'th'e rotor 24',-

with the result that the rotorat now increases its rate of rotation with respectto therotor 29;

and the vane piston 2i moves away from the abutmentv idandperforms its return stroke. Thus, in the positions progressing from Figs. 10-13, the vane piston 21: moves back away 'from'th'e'abutment' '25, expanding the displacement chamber therebetween and drawing in the fluid inthe port 55'from the manifold 5'! through the port 53 from the intake passage' The vertical dottedlines, accordingly, indicate the position of the intake As also shown" in Figs. 10-13, incl-2, the vane piston 2! moves relatively slower near the teran-intake port, is partially opened and closed at the beginning and end? of the Stroke and fully opened during itsmid'p'or ti'on;

As the appreciated that the same-operations of delivery an'd i'ntake'a're being carriedon by all three of the other vane pistons and displacement chambers. In: summary, therefore; allfo'urof the vane pistons and displacement chambers are simultane ou'sly' taking in" and delivering a quantity of fluid during 1 80" or one half a revolutionof the rotors- 28* and 24 As the intake and delivery functions' of each displacement chamber are reversed dining the next half revolution, viz.,. from. 180 to -360, the same function occurs; sothat in one complete" revolution the movement of the vane Alth'ough only one individual vane piston- 2% and one individual abutment 25 have been re pistons 21' with respect to the abutmen'ts' 25 produces twointa-kestrokes and twodelivery strokes; so that, in total, during one revolution there occur'in' the four chambers, eight intake displacements and. eight delivery displac'ementsa Fig 1 4 further illustrates the principle of-- oper--' ation of m y'i'nv'e ntion. In this geometric figure, the line CL represents the horizontal centerline' or plane in which the center 0 of the eccentric ring .25- and the'c'ommoncenter 0' of" the rotors 2d and 2 3" are relatively movable. The verticalcenter line CL represents the vertical center line or plane establishing the' center 0 ofth'e eccentric ring 26 and the vertical center line CL represents the vertical center line or plane establishirig'the common center 01 of the rotors 211 and 24; Now, assume a position where the centers 0" and O1 coincide and likewise the center lines UL and C 15 and it will be appreciated that, on rotation: of the' element's 2t; 2 and 26, al-l of them will rotate at equal angular velocities. Onthe other hand; assume that the center 0' is moved in a'- left hand direction withrespect to the center 0''. In this positionthe radii Rl'an'd R; from the center 0 to the points of pivotal connection ofthe link arms 52 and 45, are moved closertoward" each other, viz.,- from 1-80", coin-' aiding withthe center line C L and 'the' center 0 to a' lesser angle; which has here been denoted as 1-68, by way of example".

With the centers 0 and O in the spaced-apart positionsjust assumed, the system is now rotated until-the link arms take the position as shown by the dotted lines} In this position, it will be seen that the rad-i-i'RE and R1 have now increased their angular relationship, viz., to Then, on rotation. to another 90, the radii R and R have further increased their angular relationship to- 192. Thus, tabulating the-angular relationships of the radii R and BL" during a complete revohition of the rotating elements Ell, 2 4 and 26', the following is the result:

Angle of Revolution 7 R-and R Degrees Therefore; during onecompiet'e cycle of re'vblution, gthe respective rad'ii'R and R of the rotors- 29 and" 2 3' have increased and then decre'asedin their positions of angular relationship; For the sake 'of further illustration of thischange in angular relationship between the rotors 20 and 24, radial dot" and dash lines have been drawn in Figs. 6 13, inclz, from the axis or rotation of the rotors 2E] and 2 3' through the centersf of the points ofpivotal attachment of the link arms 42" and 46 thereto, respectively. It will be noted that the radial line passing through th center of the point of pivotal attachment of the link arm 42 at all times bisects the vane piston 2|; and that the radial line passing through the center of the point of pivotal attachment of the link arm 46 at all times bisects the displacement chamber adjacent the abutment 25. Thus, these radial lines in Figs. 6-13, incl, not only represent the relative angular positions of the rotors 20 and 24 during a complete revolution, but also serve as a further measurement of the relativ travel or stroke of the vane piston 2| in the displacement chamber. The angle between thes radial lines has been denoted by the reference letter C, and by comparing the change in this angle from Fig. 6 through Fig. 13,'the relative oscillatory movement between the rotors 20 and 24, as they are both bodily rotating together, will be found exemplified.

It will also be appreciated that the amount of this relative angular change is, in turn, dependent upon, and controlled by the amount of eccentricity of the ring 26 with respect to the rotors 2t and 24, or the distance of the center from the center 0'.

Thus, it will be seen that the characteristic essentials of my invention reside in the provision of a mechanism for transforming uniform velocity rotary motion into variable velocity rotary motion as between rotating elements mounted upon a common axis, whereby such elements are caused to have an oscillatory motion with respect to each other; and that when such mechanism is embodied in a pump or equivalent mechanical engine, the necessity for any addition or extrinsic valve elements or actuating mechanism therefor is eliminated because the rotation of on of the rotary elements with respect to the fixed shaft produces the required valving action for the displacement chambers. The substantial reduction in the number of moving parts of the mechanism of my invention, their simplicity and compactness of construction, and the ease and accuracy of control of the pump stroke and delivery variation are all advantageous features inherent in these general characteristic essentials.

Other modes of applying the principle the invention may be employed, change being as regards the details described, provided the features stated in any of the following, claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a pump, concentric rotary members rotatable with respect to each other, displacement chambers provided between said members, a rotatable member surrounding said rotary members mounted upon an axis eccentric of that of said rotary members, connecting elements between said rotary members and said eccentrically mounted rotatable member for transmitting variable velocity rotary motion from one to the other of said rotary members, said' rotary mem-' 8 able member for transmitting variable Velocity rotary motion from one to the other of said rotary members, said rotary members being in radial alignment, and driving means directly connected to one of said rotary members.

3.v In a pump, concentric rotary members rotatable with respect to each other, displacement chambers provided between said members, a rotatable member surrounding said rotary members mounted upon an axis eccentric of that of said rotary members, connecting elements between said rotary members and said eccentrically mounted rotatable member for transmitting variable velocity rotary motion from one to the other of said rotary members, means for varying the eccentricity of said rotary member mounted on an axis eccentric whereby to control the relative amount of rotation between said rotary members with respect to each other, said rotary members being in radial alignment, and driving means directly connected to one of said rotary members.

4. In a pump, a pair of concentric rotary members mounted on a common axis and rotatable thereon in unison but with oscillatory motion with respect to each other, a stationary shaft supporting one of said rotary members and a drive shaft directly connected to said one of said rotary members, fixed vane pistons on one of said rotary members and inter-fitting arcuate displacement chambers therefor carried by the other of said rotary members, intake and eduction passages leading from said chambers to and through said stationary shaft, and rotatable control means surrounding said rotary members and mounted on an axis eccentric to that of said rotary members so connected to said rotary members as to impart said oscillatory motion thereto.

5. In a pump, a pair of rotary members mounted on a common axis, fixedly mounted vane pistons on one of said rotary members and interfitting arcuate displacement chambers therefor carried by the other of said rotary members, a central shaft in said common axis, intake and eduction passages leading from said chambers to and through said shaft, a rotatable member surrounding said rotary members mounted upon an axis eccentric of such common axis, connecting elements between said rotary members and said eccentrically mounted rotatable member for transmitting variable velocity rotary motion from one to the other of said rotary members, said rotary members being in radial alignment, and driving means directly connected to one of said rotary members.

6. In a pump,'a pair of rotary members mounted on a common axis, fixedly mounted vane pistons on one of said rotary members and interfitting arcuate displacement chambers therefor carried by the other of said rotary members, a central shaft in said common axis, intalre and eduction passages leading from said chambers to and through said shaft, a rotatable member surrounding said rotary members mounted upon an axis eccentric of such common axis, connecting elements between said rotary members and said eccentrically mounted rotatable member for transmitting variable velocity rotary motion from one to the other of said rotary members, means for varying the eccentricity of said rotary mem ber mounted on an axiseccentric whereby to control the relative amount of rotation between said rotary members with respect to each other, said rotary members being in radial alignment, and driving means directly connected to one of said 7. In a pump, inner and. outer rotary members mounted for rotation on the same axis, a plurality of radially inwardly extending wing pistons fixed on one of said rotary members and a plurality of radially outwardly extending wing pistons on the other, said wing pistons on each of said respective rotary members having circumferential spaces between each other a greater distance than the circumferential width of the individual wing pistons to form displacement chambers between said rotary members, a central shaft in said axis intake and eduction passages leading from the spaces between said wing pistons to said shaft, and motion transmitting means surrounding said rotary member for accelerating and decelerating the rate of rotation of said rotary members with respect to each other and. during one revolution of both of said members.

8. In a pump, a pair of rotary members rotatable about a common fixed shaft, displacement chambers in one of said rotary members, and vane pistons operating in said chambers and carried by one of said rotary members an inlet passage and an outlet passage located within said shaft, ports in said shaft and in one of said rotary members in radial alignment with said chambers, said ports communicating said chambers with said passages, and motion transmitting means surrounding and connecting said rotary members for accelerating and decelerating the rate of rotation ofone of said rotary members with respect to the other and during one revolution of both of said members.

9. In a pump, a pair of rotary members rotatable about a common fixed shaft, displacement chambers in one of said rotary members, and vane pistons operating in said chambers and carried by one of said rotary members an inlet passage and an outlet passage located within said shaft, ports in said shaft and in one of said rotary members in radial alignment with said chambers, said ports communicating said chambers with said passages, motion transmitting means connecting said rotary members for accelerating and decelerating the rate of rotation of one of said rotary members with respect to the other and during one revolution of both of said members, including a rotatable member surrounding said rotary members mounted upon an axis eccentric of that of said rotary members, connecting elements between said rotary members and said eccentrically mounted rotatable member for transmitting variable velocity rotary motion from one to the other of said rotary mem-' bers, and means for varying the eccentricity of said rotary member mounted on an axis eccentric whereby to control the relative amount of rotation between said rotary members with respect to each other.

10. In a pump, a pair of rotary members rotatable about a common fixed shaft, a rotatable member surrounding said rotary members and eccentrically mounted, displacement chambers in one of said rotary members, and vane pistons operating in said chambers and carried by one of said rotary members a pair of annular passages in one of said rotary members adjacent said chambers, ports on opposite sides of said vane pistons communicating said chambers with said annular passages, those of said ports on one side of said pistons communicating with one of said annular passages, and those of said ports on the other side of said pistons communicating with the other of said annular passages, an inlet passage and an outlet passage located Withinv said shaft,

said annular passages having openings in communication with said inlet and said outlet pas.- sages in said shaft, and connecting elements between said rotary members and said eccentrically mounted rotatable member for transmitting variable velocity rotary motion from one to the other of said rotary members.

11. In a pump, a pair of rotary members rotatable about a common fixed shaft, a rotatable member surrounding said rotary members and eccentrically mounted, displacement chambers in one of said rotary members, and vane pistons operating in said chambers and carried by one of said rotary members a pair of annular passages in one of rotary members adjacent said chambers, ports on opposite sides of said vane pistons communicating said chambers with said annular passages, those of said ports on one side of said pistons communicating with one of said annular passages, and those of said ports on the other side of said pistons communicating with the other of said annular passages, an inlet passage and an outlet passage located within said shaft, said annular passages having openings in communication with said inlet andsaid outlet passages in said shaft, connecting elements between said rotary members and said eccentrically mounted rotatable member for transmitting variable velocity rotary motion from one to the other of said rotary members, and means for varying the eccentricity of said eccentrically mounted rotary member whereby to control the relative amount of rotation between said rotary members with respect to each other.

12. In a pump, inner and outer rotary members mounted for rotation on the same axis, a plurality of radially inwardly extending Wing pistons fixed on one of said rotary members and a plurality of radially outwardly extending wing pistons on the other, said Wing pistons on each of said respective rotary members having circumferential spaces between each other a greater distance than the circumferential width of the individual wing pistons to form displacement chambers between said rotary members, a central shaft in said axis intake and eduction passages leading from the spaces between said wing pistons to said shaft, a' ring member rotatably and eccentrically mounted surrounding said rotary members, means for directly driving said inner rotary member, a driving connection between said inner rotary member and said ring member, and a driving connection between said ring member and said outer rotary member whereby the latter is rotatably but oscillatably driven with respect to said inner rotary member.

13. In a pump. inner and outer rotary members mounted for rotation on the same axis, a plurality of radially inwardly extending wing pistons fixed on one of said rotary members and a plurality of radially outwardly extending wing pistons on the other, said wing pistons on each of said respective rotary members having circumferential spaces between each other a greater distance than the circumferential width of the individual wing pistons to form displacement chambers between said rotary members, a central shaft in said axis intake and eduction passages leading from the spaces between said wing pistons to said shaft, a ring member rotatably and eccentrically mounted surrounding said rotary members, means for directly driving said inner rotary member, a driving connection between said inner rotary member and said ring member, a driving connection between said ring member and said outer rotary member whereby the latter is rotatably but oscillatably driven with respect to said inner rotary member, and means for varying the eccentricity of said ring member with respect to the axis of rotation of said rotary members to control the extent of such oscillating movement.

14. In a pump, a rotary member having a plurality of radially projecting vane pistons fixed thereon, a second rotary member enclosing said rotary member and having arcuately shaped chambers receiving said pistons, a fixed shaft supporting both said rotary members, an inlet passage and an outlet passage located within said shaft, a pair of annular passages in one of said rotary members adjacent said chambers, ports on opposite sides of said vane pistons communicating said chambers with said annular passages, those of said ports on one side of said pistons communicating with one of said annular passages, and those of said ports on the other side of said pistons communicating with the other of said passages, said annular passages having openings in communication with said inlet and said outlet passages in said shaft, and motion transmitting means surrounding and connecting said rotary members for accelerating and decelerating the rate of rotation of one of said rotary members with respect to the other and during one revolution of both of said members.

15. In a pump, a rotary member having a plurality of radially projecting vane pistons fixed thereon, a second rotary member nclosing said rotary member and having arcuately shaped chambers receiving said pistons, a fixed shaft supporting both said rotary members, an inletpassage and an outlet passage located within said shaft, a' pair of annular passages in one of said rotary members adjacent said chambers, ports on opposite sides of said vane pistons communicating said chambers with said annular passages, those of said ports on one side of said pistons communicating with one of said annular passages, and those of said ports on the other side of said pistons communicating with the other of said passages, said annular passages having openings in communication with said inlet and said outlet passages in said shaft, a ring member rotatably and eccentrically mounted surrounding said rotary members, means fordirectly driving said rotary member, a connecting link between said rotary member and said ring member, is, connecting link between said ring member and said second rotary member whereby the latter is rotatably but oscillatably driven with respect to said rotary member. 7

16. In a pump, a rotary member having a plurality of radially projecting vane pistons fixed thereon, a second rotary member enclosing said rotary member and having arcuately shaped chambers receiving said pistons, a fixed shaft supporting both said rotary members, an inlet passage and an outlet passage located within said shaft, a pair of annular passages in one of said rotary members adjacent said chambers, ports on opposite sidesof said vane pistons communicating said chambers with said annular passages, those of said ports on one side of said pistons communicating with one of said annular passages, and those of said ports on the other side of said pistons communicating With the other of said passages, said annular passages having openings in communication with said inlet and said outlet passages in said shaft, a ring member rotatably and eccentrically mounted surrounding said rotary members, means for directly driving said rotary member, a connecting link between said rotary member and said ring member, a connecting link between said ring member and said second rotary member whereby the latter is rotatably but oscillatably driven with respect to said rotary member, and means for varying the eccentricity of said ring member with respect to the axis of said fixed shaft to control the extent of such oscillatory movement of said rotary hous- 17. In a pump, a rotary member having a plurality of radially projecting vane pistons fixed thereon, a second rotary member enclosing said rotary member and having arcuately shaped chambers receiving said pistons, a fixed shaft supporting both said rotary members, an inlet passage and an outlet passage located within said shaft, a pair of annular passages in one of said rotary members adjacent said chambers, ports on opposite sides of said vane pistons communicating said chambers with said annular passages, those of said ports on one side of said pistons communicating with one of said annular passages, and those of said ports on the other side of said pistons communicating with th other of said passages, said annular passages having openings in communication with said inlet and said outlet passages in said shaft, a ring member rotatably and eccentrically mounted surrounding said rotary members, means for directly driving said rotary member, a connecting link between said rotary member and said ring member, a connecting link between said ring member and said second rotary member whereby the latter is rotatably but oscillatably driven with respect to said rotary member, a bearing housing rotatably supporting and enclosing said ring member, said bearing housing being laterally movable with respect to said fixed shaft, and means for so moving said bearing housing to vary the amount of eccentricity of said ring member and thereby to control the extent of such oscillatory movement of said rotary housing.

18. In a pump, a pair of concentrically mount-- ed rotors, a plurality of fixed vane pistons carried by one of said rotors, arcuately shaped displacement chambers for said pistons carried by the other of said rotors, a rotatable ring member mounted adjacent said rotors, and link arms piv otally connecting each of said rotors, respectively, to said ring member, said link arms each being in radial alignment with one of said rotors.

19. In a pump, a pair of concentrically mounted rotors, a plurality of fixed vane pistons carried by one of said rotors, arcuately shaped displacement chambers for said pistons carried by the other of said rotors, a drive shaft directly connected to one of said rotors, a rotatable ring member mounted adjacent said rotors, and link arms pivotally connecting each of said rotors, respectively, to said ring member, said link arms each being in radial alignment with one of said rotors.

20. In a pump, a supporting housing, a pair of rotors concentrically journalled in said housing, a plurality of vane pistons fixedly carried by one of said rotors, arcuately shaped displacement chambers for said-pistons carried by the other of said rotors, a second housing movably mounted Within said supporting housing in a direction transverse to the axis of said rotors, a ring mem ber rotatably journalled in said second housin with its axis of rotation parallel to the axis of said rotors, link arms pivotally connecting each of said rotors, respectively, to said ring member,

13 conduit means at the axis of rotation of said rotors for introducing and educting fluid to be pumped to and from said displacement chambers, and means for directly driving said one of said rotors carrying said vane pistons.

THOMAS J. LESTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,149,143 Landenberger Feb. 28, 1939 2,148,282 Stevens Feb. 21, 1939 Number Number 

